The caller of Kufa called: "The prayer is a general one (which all should have attained) (al-salat jami `a). "The people gathered. Al-Hasan, peace be on him, went out. He went up on the pulpit. He praised Allah, lauded Him, and said: "Now then, indeed, Allah has enjoined jihad (fighting) on you, and has called it dislike. Then He said to the mujahidin (holy fighters): `Be patient. Indeed, Allah is with the patient.' People, you do not obtain what you like but through enduring what you dislike. I have heard that Mu'awiya has advanced against us. Therefore, may Allah have mercy on you, go out to your camp at al-Nukhayla  so that we may look and you look, we may see and you see.
The historians of the event said: "The people kept silent. They did not speak to him, nor did they answer him with a letter."
`Adi b. Hatam was the chief of (the tribe of) Tay. He was a notable leader for his glorious deeds. He was a companion of both the Prophet and 'Ali, the trustee of authority (wasi), may Allah bless them. When he saw that (attitude), he was full of anger. His voice boomed and shook the gathering people. So they turned to him to understand his words and to take care of his affair. Many people knew the history of b. Hatam al-Ta'i. They knew his righteousness, and his resistance for the truth. The leader (i.e., `Adi b. Hatam) used effective words and intense scolding. He condemned the silence of the people, and denounced their abominable weakness.
Then `Adi said: "I am `Adi b. Hatam. How ugly this attitude is! Why do you not answer your Imam, the son of the daughter of your Prophet? Where are the orators of the city? Where are their tongues that are like the penetrating swords during peace? Why do they trick like the fox during seriousness? Do you not fear Allah's disgust? Do you not feel shame for the defect and the disgrace of it (the attitude)?"
Then `Adi b. Hatam turned his face to al-Hasan and said: "May Allah achieve right guidance through you, guard you against misfortunes, and grant you success to do laudable acts. We have heard your words. We have obeyed your order. We have listened to you. We have obeyed you in what you have said and seen. Now, I am heading for our camp."
Then he said: "So whoever wants to come, let him come." Then he went out of the mosque. His riding animal was at the door (of the mosque). So he mounted it and headed for al-Nukhayla. He ordered his servant to follow him to supply him with his necessities. For this reason he was the first to go to the camp,  to set a good example to the other obedient mujahids (fighters). In (the tribe of Tay), there were a thousand fighters who obeyed `Adi in everything. 
After `Adi b. Hatam, other orators became active. They addressed al-Hasan in the same manner `Adi used. So al-Hasan, peace be on him, said to them: "May Allah have mercy on you. I still know your sincere intentions, your faithfulness, and your love. So may Allah reward you with good."
Al-Hasan, appointed his cousin, al-Mughira b. Noufal b. al-Harith b. `Abd al-Muttalib, as his successor over Kufa and ordered him to urge the people to join him at al-Nukhayla.
Al-Hasan went out with those who were with him. His going out was the first day of the declaration of jihad. In the meantime it was the strongest proof al-Hasan used to urge the people to take part in jihad.
The battalions of al-Nukhayla included the best companions from the followers (Shi'a) of al-Hasan and from the companions of his father, and the like.
Al-Mughira b. Noufal became active in urging the people to take part in jihad. The people held active festivals during the pledge of allegiance to the new Successor. It was expected for the new Succession to urge the people in Kufa to answer the summons of the Imam (i.e., al-Hasan) with enthusiasm. However, nothing of that occurred. Noteworthy, there were ready companies. They had forty thousand fighters. The Commander of the faithful (i.e., Imam 'Ali) formed them to resist the attacks of the Syrians before his death. However, these ready companies divided and most of them mutinied against al-Hasan. Also most of the armed men in Kufa followed them in disobeying al-Hasan's orders.
Some hesitating Kufan chiefs became very active during the critical moment when the attitude became serious.
The historians have mentioned the following words on the authority of al-Harith al-Hamadani, who said: "Those who wanted to go out rode with him (i.e., al-Hasan). Many people refused to go with him. They did not fulfill what they had said and promised. They deceived him as they had deceived the Commander of the faithful before him. Al-Hasan camped at al-Nukhayla for ten days. No one joined him except four thousand fighters. So he came back to Kufa to urge people. There he delivered a sermon in which he said: "You have deceived me as you had deceived those who were before me." 
I (the author) say: We do not know exactly the number of those who joined al-Hasan. However, we know that he "left Kufa with a great army" as b. Abu al-Hadid said in his book `Sharh Nahj al-Balagha.'
In the chapter entitled, `the Number of the Army', we will discuss the ideas of the historians to choose the accurate number of the soldiers of al-Hasan, peace be on him.
Al-Hasan left al-Nukhayla and reached Dir `Abd al-Rahman. He stayed there for three days. At that place other mujahidin (fighters) joined him, but we do not know their number.
As for al-Mada'in, it was at the bridgehead towards Persia and the neighboring area. Because of its geographical situation, al-Mada'in was the only area that protected the three lines that connected Kufa, Basrah, and Persia with each other. Because of its military importance, it drove back the events which the conditions of war caused. Persia was the place from which the revolts against the State started. Over Persia was Ziyad b. `Ubayd who was appointed by the Imam, and who went on his previous nature that changed every thing in him.
As for Maskan, it was the sensitive point in the history of the jihad of al-Hasan, peace be on him. That is because it was the field which al-Hasan was supposed to meet the enemy face to face. At that time it was on the far northern borders of Hashimite Iraq, or the areas dominated by the Kufan authority from this direction. At Maskan, there were agricultural lands, inhabited lands, and many famous villages such as Awana, `Ukbara, and al-`Alth that was the last village on the northern borders of Maskan . Facing al-`Alth was a village called al-Jinubiya towards which Mu'awiya and his army advanced when they left the bridge of Manbij where the two armies met.
It is known today that the situation of Maskan is at these wide plains that are situated between the village of Sumayka and the village of Balad, with the exception of Samarra.'
Maskan had nature rich in resources, near rivers, and wide plains. Because of these natural features, Maskan was the best place for war. It was, for the first time in its history, the battlefield towards which al-Hasan and Mu'awiya advanced. Then many battles between Iraq and Sham (Syria) occurred there.
Al-Hasan, peace be on him, thought that it was better for him to use al-Mada'in, because of its military importance, as a headquarters for his high command to receive military supplies from the three neighboring cities and to be at the back of his field where he met Mu'awiya and the Syrians, namely at Maskan. There were no more than fifteen leagues between the two Hashimite camps, namely alMada'in and Maskan.
That was the excellent plan of which there was no alternative for that situation of war. In this way, namely through drawing his war plans, al-Hasan has shown us that he was the inspired leader who had command of war tactics as the people of his time called. Moreover, al-Hasan used gradual steps to resist his enemy. Namely, he tested the time, chose the situations, and led the armies. All these steps have indicated that he had outstanding military talents that were equal to the talents he had in policy, loyalty, and sacrifice.
Al-Hasan, peace be on him, looked left and right. Then he considered carefully the prominent figures who were with him. They were from the leaders of his followers (Shi'a) and of his family. He wanted to choose a leader from them for his advance guards whom he determined to send to Maskan. Among the gentle ones of the tribe and the loyal Ansar (supporters), he found no one more eager and sincerer for the attitude of his cousin `Ubayd Allah  b. `Abbas b. `Abd al-Muttalib, Qays b. Sa'd b. `Abbada al-Ansari, and Said b. Qays al-Hamadani, the head of the Yemenis in Kufa. So al-Hasan confined successively the leadership to these three leaders.
`Ubayd Allah b. `Abbas was among those who were eager for war, and was indifferent to life. Religious zeal moved him, and the tribal enthusiasm stirred him up. So he was melted in his fanaticism for the Hashimite throne as the melted steel. He was among the leaders of the Hashimites. As they say :"The bereaved woman of a child is unlike the hired one." As for his outstanding backgrounds, he was the Emir of the hajj in the year 36 A.H. (according to the narration in the book al-Isaba') or in the year 39 A.H. (according to the report of al-Tabari) or he was the Emir of the hajj in both years. He was the ruler of Bahrain and the Yemen  and their subsequent parts during the lifetime of the Commander of the faithful (i.e., Imam 'Ali). The pilgrims in Mecca bore witness that he was generous. Then he was the first to pledge allegiance to al-Hasan when the people pledged allegiance to him.
According to these excellent backgrounds, Imam al-Hasan, peace be on him, had great confidence in `Ubayd Allah.  Then al-Hasan summoned him and gave him commandments which have not fully been reported to us. Rather some books have briefly mentioned them.
In these commandments, al-Hasan, peace be on him, said :"Cousin, I am going to send with you twelve thousand from the horsemen of the Arabs and the readers of the Qur'an in the city. The man from them is more than a battalion. So lead them and treat them kindly.
That is because they are the rest of the reliable companions of the Commander of the faithful. Lead them to the Euphrates. Then go on (your advancing) till you make them meet Mu'awiya face to face. If you find him (i.e., Mu'awiya), then withhold him till I come to you, for I am about to follow you. Let your news come to me every day. Ask the advice of these two (persons) (i.e., Qays b. Sa'd, and Said b. Qays). If you meet Mu'awiya, then do not start fighting against him till he starts fighting against you. If he does, then fight him. If you were struck (i.e., killed or wounded), then Qays b. Sa'd would be (the leader) over the people. If he were struck, then Said b. Qays would be (the leader) over the people.
As you see that Imam al-Hasan peace be on him, did not mean `Ubayd Allah through his commandments. Rather he meant his Companions. So he (al-Hasan) praised them, lauded their bravery, and added them to his father, the Commander of the faithful, peace be on him. With all this praise and laud, al-Hasan wanted to raise the morale, to stir up their enthusiasm, and to move their feelings. Then al-Hasan ordered `Ubayd Allah to treat them kindly. Al-Hasan gave these commandments to `Ubayd Allah to create exchangeable confidence between the commander and the army. This confidence, in the war that suffered from the paucity of the modern military regulations, was the worthiest of importance of all the elements hoped for the black (bad) days. They (the commandments) are in four joined sentences. They underline each other. Then they have only one meaning. I (the author) wonder: Is it possible for us to make use of this intentional repetition of these sentences? They, through their emphasizing, tried to uproot a certain manner in `Ubayd Allah (the new commander). That is because there were great figures with him in his army. They had glorious backgrounds and reputation. Thus they were not unable to bear his proud manner, nor were they able to bear his rudeness. For he would enjoin and prevent them. In other words they were unable to bear these qualities in that Hashimite young man who was not the best of them in merit, jihad, piety, and age. 
After that are these words of al-Hasan: "Ask the advice of these two persons." These words are another evidence for that al-Hasan intended to reform the rude behavior of `Ubayd Allah. The Imam knew that his cousin had such a kind of behavior that would hinder his victory at the battle.
I (the author) say: That rude manner, if the doubt is true, would not prevent `Ubayd Allah from being worthy of the leadership. In other words many other conditions forced him to use that rude manners, for there is a close relation between rudeness and military life in the past and present times.
In this connection, we may raise a question: Why did al-Hasan, peace be on him, appoint `Ubayd Allah over the vanguard of his army? Didn't his army have great figures such as Qays b. Sa'd b. `Abbad al-Ansari? Wasn't the latter known for his military merit, his loyalty to the family of the Prophet, may Allah bless him and his family, and his honesty?
We may answer these questions as follows:
1. When al-Hasan appointed `Ubayd Allah over the vanguard, he ordered him to ask the advice of both Qays b. Sa'd and Said b. Qays. That is what his clear commandments indicate. Through this measure, al-Hasan was able to avoid preferring `Ubayd Allah to the others. For he would be criticized for this preference. In the meantime this preference would affect that attitude. In this way the leadership became a consultation among the three persons who were the most appropriate ones of al-Hasan's men. Among these prominent figures, who were known for their leadership at the battle fields, loyalty, jihad, and back grounds, were Abu Ayyub al-Ansari, Hujr b. `Adi al-Kindi, `Adi b. Hatam al-Ta'i, and the like. We have already mentioned them.
Generally speaking, al-Hasan gave priority to `Ubayd Allah, who was al-Hasan's and the Prophet's cousin, may Allah bless him and his family, over the two other leaders. He appointed him as a leader only in name. He ordered him to ask the advice of Qays and his companion, as we have mentioned above. These steps put an end to any disagreement on the leadership or any competition for it.
2. Among the excellent precautionary measures for the general situations at that time was that no one would be a leader with al-Hasan but a Hashimite one.
To explain that, we may say that the intense weakness that accompanied the matter of al-Hasan in Kufa was still very ominous in his consideration. So al-Hasan had to take possible measures to avoid in his present and future times, the censure of the people, their accusing him of an error, and their criticism. It is easy for people to accuse someone of an error or to criticize him when they find weakness, failure, and deprivation in him. If the matter of al-Hasan in Maskan had failed, the people would have blamed him for that failure. They would say that if the leader had been from the family of al-Hasan, he would have been the most appropriate person for enduring the great adversities, and the matter would have not come to this result.
So al-Hasan was right when he got ready for the disasters of that time through appointing a Hashimite leader. This measure was very important.
3. `Ubayd Allah was more angry with Mu'awiya than any other man. He was angrier with him than Qays and the son of Qays. That is because `Ubayd Allah's two sons were killed when Bisr b. Artat attacked the Yemen. (This event is among the famous events in history.)
Thus it was very appropriate for al-Hasan to choose such a leader who was full of anger, and was eager to fight against the killer of his two sons.
The majority of the army of the vanguard headed by `Ubayd Allah was from the army which the Commander of the faithful prepared in Kufa to fight against the Syrians. Its worth mentioning that, Qays b. Sa'd b. `Abbada was the commander of this army during the lifetime of the Commander of the faithful (i.e., Imam 'Ali), peace be on him. 
These backgrounds were of great importance in strengthening the links between the commander and his soldiers. It was easy for the commander who had great influence on his soldiers to incline, whenever he wanted, to free conduct. This kind of freedom would indicate that there was no positive relation between the commander and the Supreme Authority. So al-Hasan had to be careful of such a position, for it was the most import thing during that attitude.
Although we respect our master Qays very much, we do not deny his personal abilities that would make him incline to such a kind of free conduct.
We do not forget that Qays, on the day when he headed this army, stood among his soldiers and ordered them to choose either following the Imam's Peace Treaty or going on fighting against Mu'awiya without an Imam.
Accordingly, Imam al-Hasan carried out the best two ideas. In other words, he appointed a person as a commander for his army. In the meantime he made `Ubayd Allah b. `Abbas a military adviser to make use of his abilities and cleverness.
I (the author) say: Appointing Qays as a successor after `Ubayd Allah did not harm this policy (i.e., al-Hasan's policy). That is because Qays would, after the killing of his predecessor in the battlefields of Maskan according to the items of the convention, follow the plan, which his predecessor had followed. For the conditions of the battle between the two parties (i.e., al-Hasan and Mu'awiya) did not permit him to change the plan. Moreover, he (Qays) would be under the direct leadership of the Imam (who was) the high leader. From what we have already mentioned, we have known that the Imam promised the vanguard of his army that he was about to follow them.
After this (explanation), there was no danger in appointing Qays as a successor after `Ubayd Allah as long as the former was ordered to follow a certain plan, and was under the direct supervision of the Imam.
 Little date palm, a place near Kufa, towards Sham (Syria). I (the author) say: Today, there is, towards Karbala', a building called Khan al-Nukhayla. There are twelve miles between it and Kufa.
 Ibn Abu al-Hadid, Sharh Nahj al-Balagha, vol. 4, p. 14.
 Al-Ya'qubi, Ta'rikh, vol. 2, p. 171.
 Al-Rawandi, al-Kharaij wa al-Jaraih, p. 228, (Iran).
 It was the Sassanid capital. It lasted for one thousand years. It was the inheritor of Babil (Babylon) in greatness. Today, none of its ruins has remained but Taq Kasra, and the Shrine of the great Companion (Salman al Farisi), may Allah have mercy on him. There were seven facing cities, namely they faced each other on the banks of Tigris. The Muslims conquered it in the year 15 A.H. At that time it was the capital of all the Persian East. So in the Western side were Saluqiya, Darzjan, Bahrsir, and Jindisabur (Kauka) in the district of Mazlam Sabat which was related to Nahr al-Malik (the River of the king). And in the Eastern side were Asfanbar, Romya, and Tishfon which had Taq Kasra.
More than one hundred years had passed before the extinction of al Mada'in because of the foundation of Baghdad in the year 150 A.H. During that period of time, al-Mada'in supplied Kufa with industries, resources, and crops. That was through sending Persian friends to it, who became Muslims.
Al-Mada'in followed the example of the family of Muhammad, may Allah bless him and his family, from the day when Salman became a governor over it. Also in the seventh century A.H., al Mada'in was a village which no one inhabited but the eager Shi'a.
Al-Mas'udi mentioned al-Mada'in when he mentioned Iraq. He said: "And the cities of Iraq were al Mada'in and the surrounding cities. The people of al-Mada'in had the most moderate colors, the purest perfumes, the best tempers, and the most obedient natures. In them were inclusive virtues, and peerless sound deeds."
 The name of al-Tasuj from which Awana was. It was situated on the bank of the river Dujayl. There were many gardens of date- palms and trees in it. Abu al-Faraj al-Sawadi (from the poets of the sixth century A.H.) meant it when he said:
And they regarded it as virgin grew in Awana
Hidden from her fiancees with the vessels.
There were ten leagues between Maskan and Baghdad. At Maskan, a battle took place between `Abd al-Malik b. Marwan and Mas'ab b. al-Zubayr in the year 72 A.H. Mas'ab and Ibrahim b. Malik al Ashtar were killed at that battle. They were buried where they were killed. Their graves are still visible. There is a humble dome over the two graves. The Arabs of Sumayka call this dome the Grave of Shaykh Ibrahim (Qabr Shaykh lbrahim). There are about sixty kilometers between this dome and Baghdad, and ten kilometers between it and Tigris. So Maskan was the area that surrounded this grave, including the river Dujayl. Also Awana was there.
 In al-Ahkam al-Sultaniya, al-Mawardi has mentioned the following on the authority of al-Hamawi, who said: "Al-`Alth is the first part of Iraq from this direction." I (the author) say: Al-`Alth is situated between `Ukbara and Samarra'. `Ukbara is among the villages of Dujayl, near Awanan.
 Al-Mufid, al-Irshad, p. 170. Ibn Abu al-Hadid, Sharh Nahj al Balagha, vol. 4, p. 14. Al-Ya'qubi, Ta'rikh, vol. 2, p. 191.
Another historian has mentioned that it was his brother `Abd Allah b. 'Abbas. That is incorrect, for `Abd Allah was not in Kufa during the days of the Succession of al-Hasan. Rather, he was in Mecca, and wrote to al-Hasan a letter in which he hinted at war. You find details about him in `Sharh Nahj al-Balagha', vol. 4, pp. 8-9. If `Abd Allah was in Kufa at that time, his name would not be hidden during those events. In his book `al-Ta'rikh', vol. 6, p. 81, al-Tabari said: "In the opinion of all historians, `Abd Allah b. 'Abbas went out of Basrah and reached Mecca. Some historians have denied that and claimed that the Commander of the faithful, peace be on him, appointed him a governor over Basrah. He governed it till he (the Commander of the faithful) was killed. (He was still a governor over Basrah) after the killing of 'Ali till al-Hasan made peace (with Mu'awiya). Then he left (Basrah) at that time for Mecca." I (i.e., the author) say: `Abd Allah b. 'Abbas was not in Basrah. If he had been there, the army would not have delayed. For al-Hasan was in a pressing need of it in al-Mada'in. Ibn al-Athir (vol. 3, p. 166) has underlined that `Abd Allah b. `Abbas left 'Ali during his lifetime.
We think that it is the similarity between the two brothers in father and name has made such an error in attributing the leadership to `Abd Allah. Another historian made a mistake so that he has attributed the leadership of the vanguard to Qays b. Sa'd who was the leader of the fighters who were in front of the vanguard as Ibn al-Athir has mentioned. That maybe the reason for this imagination. Then think.
 Some historians tried to doubt the historical backgrounds of `Ubayd Allah through the event that forced him to go out of the Yemen. It is an act of truthfulness to admit that the garrison of the Yemen was too weak to resist the attack of Bisr b. Artat at that time. Moreover, some of the Yemenis deserted the Hashimite authority. They wrote letters to Mu'awiya. They dismissed their Emir Said b. Nimran from the army. And they disobeyed their ruler `Ubayd Allah. All these factors and others indicate that `Ubayd Allah was innocent of the doubts. If `Ubayd Allah had tried to resist Bisr, the latter would have been able to defeat him with the help of the `Uthmanis in the Yemen. `Ubayd Allah did not do more than what his peers did in Mecca and Medina when they escaped from Bisr. The governor of Mu'awiya over the three capitals attacked the people where in. So he killed about thirty thousand innocent people.
We have known that `Ubayd Allah intended to go to Kufa when he left the Yemen. And if he had been suspicious, he would have not headed for Kufa. Besides we have known that Said b. Nimran apologized to the Commander of the faithful, peace be on him, when he said to the latter: "I summoned the people (i.e., the people of the Yemen) to fighting. A group of them answered me. So I fought weakly. Then the people left me, and I went away. I (the author) say: Will the experience of b. Nimran not correct the apology of `Ubayd Allah b. `Abbas? That is because the backgrounds of this man had no defect. Therefore, no wonder when al-Hasan was satisfied with him because of his reliable backgrounds.
 Ibn Abu al-Hadid, vol. 4, p. 14. Al-Mufid, al-Irshad, pp. 168-169. Al Ya'qubi, Ta'rikh, vol. 2, p. 191.
Only al-Ya'qubi did not mention the third leader from the leaders of the vanguard, then he said: "Al-Hasan ordered `Ubayd Allah to obey the order and idea of Qays b. Sa'd. So `Ubayd Allah advanced towards the Island (i.e., Mesopotamia). When Mu'awiya heard of the killing of 'Ali, peace be on him, he headed for Mousil eighteen days after the killing of 'Ali. I (the author) say: Mousil was among the villages of Maskan. Our master Muhammad b. Imam 'Ali al-Midi was buried near Mousil as al-Hamawi has mentioned in his book `al-Mujam'. It is other than the present city of Mousil (in Iraq). There is no difference between what al-Ya'qubi and what the others reported about limiting the situation where the army of Mu'awiya stopped during his war against al-Hasan. That is because Mousil, al Haywada, al-Jinubiya were all among the villages of Maskan at that time. Maybe, the army occupied all these villages, so their names have been mentioned in various reports. Also some reports have been confined to some names as you see. As for us, we have only chosen al-Jinubiya depending on the letter Qays b. Sa'd wrote to al-Hasan as we will mention in the following chapters.
 `Ubayd Allah b. `Abbas was 39 years old on the day when he led this army.
 Ibn Kathir, Ta'rikh, vol. 8, p. 14.